add unit test for case when SLL needs to see EOF

tool/playground/T-input

@@ -1 +1 @@
-abc
+34 abc

tool/playground/T.g

@@ -1,5 +1,11 @@
 grammar T;
 
-s : ID ;
-
+s : a | b ;
+a : c ID ;
+b : c INT ID ;
+c : INT
+  |
+  ;
+INT : [0-9]+ ;
 ID : [a-z]+ ;
+WS : [ \r\t\n]+ -> skip ;

tool/test/org/antlr/v4/test/TestFullContextParsing.java

@@ -32,7 +32,7 @@ package org.antlr.v4.test;
 
 import org.junit.Test;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
 
 /*
 	 cover these cases:
@@ -121,6 +121,30 @@ public class TestFullContextParsing extends BaseTest {
 					 this.stderrDuringParse);
 	}
 
+	@Test public void testSLLSeesEOFInLLGrammar() {
+		String grammar =
+			"grammar T;\n"+
+			"s @after {dumpDFA();}\n" +
+			"  : a ;\n" +
+			"a : e ID ;\n" +
+			"b : e INT ID ;\n" +
+			"e : INT | ;\n" +
+			"ID : 'a'..'z'+ ;\n"+
+			"INT : '0'..'9'+ ;\n"+
+			"WS : (' '|'\\t'|'\\n')+ {skip();} ;\n";
+		String result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
+								   "34 abc", true);
+		String expecting =
+			"Decision 0:\n" +
+			"s0-INT->s1\n" +
+			"s1-ID->s2\n" +
+			"s2-EOF->s3^\n"; // Must point at accept state
+		assertEquals(expecting, result);
+		assertEquals("line 1:6 reportAttemptingFullContext d=0, input='34abc'\n" +
+					 "line 1:0 reportContextSensitivity d=0, input='34'\n",
+					 this.stderrDuringParse);
+	}
+
 	@Test public void testFullContextIF_THEN_ELSEParse() {
 		String grammar =
 			"grammar T;\n"+